Adjustable illuminated tellurian



May 1, 1951 I D. GREENFIELD ADJUSTABLE ILLUMINATED TELLURIAN Filed May 13, 1949 I N V EN TOR. DA wo @eEE/vF/Ez. 0,

Patented May 1, 1951 UNITED STATES PATENT OFFICE ADJUSTABLE ILLUMINATED 'I.EILLURIAJNI' David Greenfield, Los Angeles, Calif.

Application May 13, 1949, Serial No. 92,984

Y 8 Claims. 1

This invention relates generally to an instructional apparatu for illustrating the incidence of solar light on the earth and relates more particularly to a device wherein a source of light simulating the sun may be accurately positioned with respect to the axis and equator of a rotatable globe representing the earth.

Prior devices have sought to illustrate the relation between the sun and the earth, the succession of the seasons, the time relationship betwe n various points on the earth and similar phenomena. Such devices have in general been complex in structure and mechanism, and consequently too expensive for domestic use.

My invention, on the other hand, is simple and reliable in design and at the same time is well ada ted for visual demonstration of solar phenomena. Its economy of manufacture and ease of adjustment commend it for use in the home, where children may early learn fundam ntal astronomical principles.

It is an object of this invention to d sclose a novel and simple mechanism for demonstrating the effects of the suns radiation on the earth.

Another object is to disclose a device by which the mean-solar time at any point on the earth may be quickly and conveniently determined.

A further object of my invention is to disclose an apparatus which continuously shows which.

portions of the earth are experiencing sunrise, noon and sunset.

A still further obiect i to di close an apparatus illustrating the causes of seasonal variations in length of day, average temperature and other ph nomena manifesting cyclical changes' These and other objects and purposes will become clear from a reading of the following description taken in connection with the accompanying drawing in which:

Fig. 1 is an elevational view of my invention.

Fig. 2 is a detailed elevational view of my invention partially in section.

Fig. 3 is a sectional view taken on line III-III of Fig. 2.

Fig. 4 is a perspective view of the lower end of the arcuate arm of my invention.

Generally speaking, my invention includes a globe arranged for rotation about a vertical axis through its poles, an external source of light arranged to illuminate the globe and means for positioning the light source at any point in an arc concentric with the globe, simulating the suns position at any point in its travel from the Tropic of Cancer to the Tropic of Capricorn.

Referring in detail to the drawings, globe Ill 2 i is supported by shaft II which is preferably dis posed vertically. Shaft I I is journaled at l2 to hollow sleeve member l3 and may be driven'by electric motor l4 through a gear train indicated generally at I5 and including final drive shaft l6. Motor I4 is supplied with electric power by leads 32 connected through switch 33 and leads 34 to an external source of power not shown.

Shaft II is connected to final drive shaft l6 by frictional connection ll. Globe l0 will thus be normally rotated by the action of electric motor M'through gear train [5 and final drive shaft 15, but globe llJ may be'rotated by hand when desired. Hollow sleeve member I3 is fixed to base 20, as by threaded connection 2!.

Formed in base 2!) is arcuate slot 22 and slidably engaged within said slot is hollow arcuate arm 23 which is provided at its lower end with means for frictionallycontacting the inner walls of slot 22. Said means, as seen in Fig. 4, preferably include projecting fingers 25 and 25' which springingly engage the inner vertical walls of slot 22, thus retaining arcuate arm 23 in any selected position in slot 22.

Onthe outer-end of arm 23 is a light source indicated generally by 21 and including conventional electric lamp 28 and reflector 29. The shape of reflector 29 is preferably paraboloidal as shown, lamn 28 being disposed at the focus of reflector 29 so that substantially collimated light falls on globe Ill. Lamp 28 is supplied with electric power through electric cord 32 and switch 3!, said electric cord being contained within arcuate arm 23. The outs de diam ter of qrefiector 29 is preferably made substantially equal to the diameter'of globe I l.

Arcuate arm 23 contains on its outer surface a series of designations of calendar months 24 and a small mark corresponding to the 21st day of each month orpair of months. The marks are intended to be read by reference to edge 26 of base 20 where arcuate arm 23 emerges from arcuate slot 22. Thus lightsource 21, simulating the sun, may assume any position corresponding to the suns travel from the Tropic of Cancer to the V Tropic of Capricorn, and the proper position of providing additional markings 85 between the main monthly scale divisions substantially corresponding to weekly time intervals between the major monthly scale indicia. The user is thereby enabled more conveniently and accurately to adjust arcuate arm 23 to the date desired to be illustrated.

I may also provided equatorial time band 36, preferably constrycted of a transparent material and mark'ejdias at 31 with hours pi? the dayuni-1- formly arranged" around the circumference of globe I0. time band 36 on the side of globe l0 closest to light source 21. Time bandil3filrissumiortedablf' arcuate support members 38 and iflf preferably made of transparent material, said arcuate mem Noon will, of course, be indicated on: v

I claim: 7 1. An instructional apparatus comprising: a base including an arcuate slot; a vertical shaft rotatably mounted in said base; a terrestrial globe carried by said shaft and having north and south poles and an equator, said shaft being colinear with a line joining said poles; a yoke fixed to said base including two oppositely disposed symmetrical arcuate support members eX teriding upwardlyto the equatorial plane of said globe; a narrow equatorial time belt encircling said globe and spaced therefrom carried by said arcuate support members, said belt bearing there- -.on.anl-rhourly'-spaced mean solar time scale; a

bers 38 and 38 being'fixed at their lower ends to hollow sleeve member I3. It is understood that time band 36 remains stationary at all times.

I may also provide movable meridian 39 pivotally mounted at north pole 4'0? and" at journal I-Z at theisouth pole; 4 r

. In thenormal" operation of my invention, motor l l is connected to an 'externalsource of electricpower throughfleads 32 and 34' and switch 33, a's'abov'e describedr Globell] may then'b'e manu'ally adjusted so that the mean solar time of any place'or'i earth,as indicated' by equatorial time band 36, corresponds to the actual position'of'the earth and said globe will then be continuously driven so that the surface of globe In closest to light source :21'alwaysrepresentsthat portion of the e'arthwhere it isnoon by; mean solar time;

When eac -Miami) 28 is then energized, a true and vivid illustration is provided of solar phenomena; Thus the portions "offtheearth where the sun is just rising orj iist setting may be immediately seen, If it'is'dsired to determine the r'ne'ar'i solar timefqfaily'pointomthe earth, it is i e ry to s t I -s za le m rl an, 21 ov r i d s P i t nd, i di he i msa d 'cat d on time be d. at he, i ter eciion oi i e band, a and meridian 39. o 4 V The phenomenon of seasonal variations in, the i 'st'h ofdar isht hou .i l i e ise conv n e t yillustrated. Light source, ,21, ay be .manually ,ed; to, any position "it; a; vertical arcQeXtend- 111 4.23 /2 above and' below, the equatorial plane i-elob l xample; when; gh surrea is adiustedoits no hernmo sitio so h t calibrated :markingZQ .correspondingtothemonth 01 J une-is-opposite edge 26;of ,base2-i l-, the illumi nation of globe I'D; illustratesithevsummer solstice andithe causelofi thetlonger days, and warmer temperatures obtaining in the northern i hemi'- sphere at'itha't time of yearcar! be readily understoodl'} U Y Thus it"willbfe seen that'I hayeprovided an inexpensive andeasily-adjusteddevice for ill'us-l i p fi ixstla chan s-W Mo el. J 4 mar he dr vin n t/cigar; ve m ai le tric. clo kseared. down i i-a lltldizratiolby searltrainl l rico lamp: 251mg? t course, bet-r i y: wh n urnedg uta clj maabof; atompar ely Small wattage so, that itmay. be left illuminatedrat all times;: Under these-lattenconditionsespecially ventniis anornamental it ed plelv l fll ligh at he pps .ded' aim movable, meridian pivotally attached to north and south poles of said globe and rotatable in a Sphereqhavinga :radius greater than that of said globeg an arcuate arm slidably engaged within said arcuate slot and extending outwardly thereof, said slot and arm being concentric with said globe and said, arm bearing thereon a scale calibrated from summer to winter solstices; a light source mounted on the outer end of said arm and arrangedto illuminate said globe, said light-source having adiameter substantially'equal to the. diameter. of the globe; means for retain ing said arm atselected positions within said slot whereby the. center of. said light source may be placed and maintained at any desired point in an arc concentric with said globeand coplanar therewith, said are extending 23 above and below the equatorial planeof said'globe; and means for imparting-diurnal rotation to said. shaft and globe, said means including a source ofrotational power and africtional connection whereby said globe may be manually rotated at will;

2; An instructional apparatus of" the character stated in claim 1 wherein said light source includes arefiector'adapted to illuminate-said globe with substantially collimated light.

3. In an instructional apparatus for illustrating'the incidence of solar light: on the earth, the combination of: a base provided 'witha terrestrial" globe having I poles and an equator, said-globe being rotatable relative to said base about astationary vertical axis; a source of light external to' theglobe having a diameter substantially equal to the diameter of said globe; and adjustable supporting -means extending from the. base for selectively positioning the center of said light source in anarc concentric with said" globe,- said are being coplanar with the-axis-of rotation of said globe and extending 23 above and below the equatorial plane of said globe; r

4;; An instructional'apparatus in accordance with claim 3,-w'herein said supporting means is provided with indicia of calendar dates correlated to the angular; position of the center of said light source with respect to the equatorial plane of 'said globel 5. An instructionalapparatus-in accordance with claim 3, includingadrive means within the base and a frictional driving connection between the drive means and the globe.

6. In an instructional apparatus for illustratin'g the incidence of solar lighten the earth, the combination of:

vertical "axis through said poles; an electric motor for impartingdiurnal rotation to said globe; a. source. ofsubstantially collimated' light external to thexglobelhaving-a diameter substantially; equal tqxathe, diameter 1 of said globe; and

a base provided with aterrestrial globe having poles and an equator 0 and arranged for rotation about a stationary means for selectively positioning the center of said light source in an arc concentric with said globe, said are being coplanar with said axis and extending 23%; above and below the equatorial plane of said globe.

7. An instructional apparatus in accordance with claim 6, including two symmetrically disposed arcuate support members fixed to said base and a narrow, stationary, circular equatorial time band carried by said arcuate support 10 members encircling said globe and uniformly spaced therefrom.

8. An instructional apparatus in accordance with claim '7, including a movable meridian pivotally attached to said poles and having a radius 26 greater than that of said globe.

DAVID GREEN'FIELD.

6 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 202,590 Schedler Apr. 16, 1878 2,059,031 Replogle Oct. 27, 1936 2,287,594 Barbagelata Mar. 25, 1941 FOREIGN PATENTS Number Country Date 425,108 Great Britain Mar. 4, 1935 

